WO1996025446A1

WO1996025446A1 - Biodegradable polymers, process for producing them and their use in preparing biodegradable mouldings

Info

Publication number: WO1996025446A1
Application number: PCT/EP1996/000457
Authority: WO
Inventors: Volker Warzelhan; Gunter Pipper; Ursula Seeliger; Peter Bauer; Udo Pagga; Motonori Yamamoto
Original assignee: Basf Aktiengesellschaft
Priority date: 1995-02-16
Filing date: 1996-02-03
Publication date: 1996-08-22
Also published as: EP0809666A1; EP0809666B1; ES2147918T3; EP0809666B2; DK0809664T3; DE59605251D1; EP0809664B1; DE19505185A1; US5889135A; JPH11500157A; WO1996025448A1; JP3471810B2; DE19505186A1; EP0809664A1; KR19980702244A

Abstract

Biodegradable polyesters P1 obtainable through the reaction of a mixture consisting essentially of: (a1) a mixture consisting essentially of 35 to 95 mol.% adipic acid, ester-forming derivatives thereof or mixtures thereof, 5 to 65 mol.% terephthalic acid, ester-forming derivatives thereof or mixtures thereof, and 0 to 5 mol.% of a compound containing sulphonate groups, in which the sum of the individual mol percentages is 100; and (a2) a dihydroxy compound selected from the group consisting of C2-C6alkane diols and C5-C10cycloalkane diols, the molar ratio of (a1) to (a2) being in the range from 0.4:1 to 1.5:1, provided that the polyesters P1 have a molecular weight (Mn) in the range from 5000 to 50 000 g/mol, a viscosity index in the range from 30 to 350 g/ml (measured in o-dichlorobenzol/phenol (weight ratio 50/50), at a concentration of 0.5 wt.% polyesters P1 at a temperature of 25 °C) and a melting point in the range from 50 to 170 °C, and with the further provisos that from 0.01 to 5 mol.% related to the molar quantity of the component (a1) used of a compound D with at least three groups capable of ester formation are added to product the polyesters P1 and that the polyesters P1 contain both hydroxyl and carboxyl terminal groups, the molar ratio of carboxyl to hydroxyl terminal groups being greater than one. The invention also relates to further biodegradable polymers and thermoplastic casting compounds, process for their production, their use in the manufacture of biodegradable casting compounds and adhesives, biodegradable mouldings, foams and blends with starch obtainable from the polymers or casting compounds of the invention.

Description

Biodegradable polymers, processes for their production and their use for the production of biodegradable moldings

description

The present invention relates to biodegradable polyester P1, obtainable by reaction of a mixture consisting essentially of

(al) a mixture consisting essentially of

35 to 95 mol% of adipic acid or ester-forming derivatives thereof or mixtures thereof,

5 to 65 mol% of terephthalic acid or ester-forming derivatives thereof or mixtures thereof, and

0 to 5 mol% of a compound containing sulfonate groups,

the sum of the individual mol percentages being 100 mol%, and

(a2) a dihydroxy compound selected from the group consisting of C ₂ -C ₆ alkanediols and Cs-Cirj-cycloalkanediols,

the molar ratio of (al) to (a2) being selected in the range from 0.4: 1 to 1.5: 1, with the proviso that the polyester P1 has a molecular weight (M _n ) in the range from 5000 to 50,000 g / mol, a viscosity number in the range from 30 to 350 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight polyester PI at one temperature of 25 ° C) and have a melting point in the range of 50 to 170 ° C, and with the further proviso that from 0.01 to 5 mol%, based on the molar amount of component (al) used, a Ver¬ uses bond D with at least three groups capable of ester formation for the production of the polyester P1, and the further requirement that the polyester P1 have both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being chosen to be greater than one.

Furthermore, the invention relates to polymers and biodegradable thermoplastic molding compositions according to subclaims, processes for their production, their use for producing biodegradable moldings and adhesives, biologically Degradable moldings, foams and blends with starch, obtainable from the polymers or molding compositions according to the invention.

Polymers that are biodegradable, i.e. which decay under environmental influences in a reasonable and verifiable period of time have been known for some time. The degradation usually takes place hydrolytically and / or oxidatively, but mostly through the action of microorganisms such as bacteria, yeasts, fungi and algae. Y.Tokiwa and T. Suzuki (Nature, Vol. 270, pp. 76-78, 1977) describe the enzymatic degradation of aliphatic polyesters, for example also polyesters based on succinic acid and aliphatic diols.

EP-A 565,235 describes aliphatic copolyesters containing (-NH-C (O) O -) groups ("urethane units")

Copolyesters of EP-A 565,235 are obtained by reacting a prepoly ester - obtained by reacting essentially succinic acid and an aliphatic diol - with a diisocyanate, preferably hexamethylene diisocyanate. The reaction with the diisocyanate is necessary according to EP-A 565,235, since the polycondensation alone gives only polymers with molecular weights which do not have satisfactory mechanical properties. The decisive disadvantage is the use of succinic acid or its ester derivatives for the preparation of the copolyesters, because succinic acid or its

Derivatives are expensive and not available in sufficient quantities on the market. In addition, when using succinic acid as the only acid component, the polyesters produced from it are broken down extremely slowly.

From WO 92/13019 copolyesters based on predominantly aromatic dicarboxylic acids and aliphatic diols are known, at least 85 mol% of the polyester diol residue consisting of a terephthalic acid residue. The hydrophilicity of the copolyester is increased and the crystallinity is reduced by modifications such as the incorporation of up to 2.5 mol% of metal salts of 5-sulfoisophthalic acid or short-chain ether diol segments such as diethylene glycol. According to WO 92/13019, this is intended to enable biodegradation of the copolyesters. A disadvantage of these copolyesters, however, is that biodegradation by microorganisms has not been demonstrated, but rather only the behavior towards hydrolysis in boiling water or in some cases also with water at 60 ° C. has been carried out.

According to Y.Tokiwa and T.Suzuki (Nature, Vol. 270, 1977 or J. of Appl. Polymer Science, Vol. 26, pp. 441-448, 1981) it can be assumed that polyesters which are largely aromatic Dicarboxylic acid units and aliphatic diols, such as PET (polyethylene terephthalate) and PBT (polybutylene terephthalate), are not enzymatically degradable. This also applies to copolyesters that contain blocks made up of aromatic dicarboxylic acid units and aliphatic diols.

Witt et al. (Handout for a poster at the International Workshop of the Royal Institute of Technology, Stockholm, Sweden, from April 21 to 23, 1994) describe biodegradable copolyesters based on 1,3-propanediol, terephthalic acid ester and

Adipic or sebacic acid. A disadvantage of these copolyesters is that moldings produced therefrom, in particular films, have inadequate mechanical properties.

The object of the present invention was therefore biological, i.e. by microorganisms to provide degradable polymers which do not have these disadvantages. In particular, the polymers according to the invention should be producible from known and inexpensive monomer units and should be water-insoluble. Furthermore, it should be possible to obtain customized products for the desired applications according to the invention by specific modifications such as chain extension, incorporation of hydrophilic groups and branching groups. The biological degradation by microorganisms should not be achieved at the expense of the mechanical properties, in order not to limit the number of application areas.

Accordingly, the polymers and thermoplastic molding compositions defined at the outset were found.

Furthermore, processes for their production, their use for the production of biodegradable moldings and adhesives, and biodegradable moldings, foams, blends with starch and adhesives, obtainable from the polymers and molding compositions according to the invention, have been found.

The polyesters P1 according to the invention are characterized by a molecular weight (M _n ) in the range from 5,000 to 50,000, preferably from 6,000 to 45,000, particularly preferably from 8,000 to 35,000 g / mol, a viscosity number in the range from 30 to 350, preferably from 50 to 300 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polyester PI at a temperature of 25 ° C.) and a melting point in the range from 50 to 170, preferably from 60 to 160 ° C, and the further proviso that the polyester P1 have both hydroxyl and carboxyl end groups, the molar ratio of Carboxyl end groups to hydroxyl end groups choose greater than one, preferably greater than two.

The polyester P1 is obtained according to the invention by using a mixture consisting essentially of

(al) a mixture consisting essentially of

35 to 95, preferably 45 to 80 mol% of adipic acid or ester-forming derivatives thereof, in particular those

Di-Ci-Cβ-alkyl esters such as dimethyl, diethyl, dipropyl, dibutyl, dipentyl and dihexyl adipate, or mixtures thereof, preferably adipic acid and dimethyl adipate, or mixtures thereof,

5 to 65, preferably 20 to 55 π.ol%, terephthalic acid or ester-forming derivatives thereof, in particular the di-Ci-Cε-alkyl esters such as dimethyl, diethyl, dipropyl, dibutyl, dipentyl or dihexyl terephthalate, or mixtures thereof , preferably terephthalic acid and dimethyl terephthalate, or mixtures thereof, and

0 to 5, preferably from 0 to 3, particularly preferably from 0.1 to 2 mol% of a compound containing sulfonate groups,

the sum of the individual mol percentages being 100 mol%, and

(a2) a dihydroxy compound selected from the group consisting of C ₂ -C ₆ -alkanediols and Cs-Cio-cycloalkanediols,

wherein the molar ratio of (al) to (a2) is selected in the range from 0.4: 1 to 1.5: 1, preferably from 0.6: 1 to 1.1: 1.

The sulfonate group-containing compound used is usually an alkali metal or alkaline earth metal salt of a sulfonate group-containing dicarboxylic acid or its ester-forming derivatives, preferably alkali metal salts of 5-sulphoisophthalic acid or mixtures thereof, particularly preferably the sodium salt.

According to the invention, the compound used as dihydroxy compounds (a2) is a compound selected from the group consisting of C ₂ -C 6 -alkanediols and Cs-Cio-cycloalkanediols, such as ethylene glycol, 1,2-, 1,3-propanediol, 1,2 -, 1,4-butanediol, 1, 5-pentanediol or 1, 6-hexanediol, especially ethylene glycol, 1,3-propanediol and 1,4-butanediol, cyclopentanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and mixtures thereof.

Furthermore, according to the invention from 0.01 to 5, preferably from 0.05 to 4 mol%, based on component (al), at least one compound D having at least three groups capable of ester formation is used.

The compounds D preferably contain three to ten functional groups which are capable of forming ester bonds. Particularly preferred compounds D have three to six functional groups of this type in the molecule, in particular three to six hydroxyl groups and / or carboxyl groups. Examples include:

Tartaric acid, citric acid, malic acid;

Trimethylolpropane, trimethylolethane;

Pentaerythritol; Polyether triols;

Glycerin;

Trimesic acid;

Trimellitic acid, anhydride;

Pyromellitic acid, dianhydride and hydroxyisophthalic acid.

When using compounds D which have a boiling point below 200 ° C., a fraction of the polyester P1 can be distilled off from the polycondensation mixture before the reaction. It is therefore preferred to add these compounds in an early process stage, such as the transesterification or esterification stage, in order to avoid this complication and to achieve the greatest possible regularity of their distribution within the polycondensate.

In the case of compounds D boiling above 200 ° C., these can also be used in a later process step.

By adding the compound D, for example, the melt viscosity can be changed as desired, the impact strength increased and the crystallinity of the polymers or molding compositions according to the invention reduced.

The production of the biodegradable polyester PI is known in principle (Sorensen and Campbell, "Preparative Methods of Polymer Chemistry", Interscience Publishers, Inc., New York, 1961, pages 111 to 127; Encyl. Of Poly. Science and Eng. , Vol. 12, 2nd Ed., John Wiley & Sons, 1988, pp. 1 to 75; Kunststoff-Handbuch, Volume 3/1, Carl Hanser Verlag, Munich, 1992, pp. 15 to 23 (production of polyesters); WO 92/13019; EP-A 568,593; EP-A 565,235; EP-A 28,687), so that further details are unnecessary.

For example, the reaction of dimethyl esters of component a1 with component a2 ("transesterification") at temperatures in the range from 160 to 230 ° C. in the melt at atmospheric pressure is advantageously carried out under an inert gas atmosphere.

A molar excess of component a2, based on component al, is advantageously used in the production of the biodegradable polyester P1, for example up to 2 1/2 times, preferably up to 1.67 times.

The biodegradable polyester P1 is usually prepared with the addition of suitable, known catalysts such as metal compounds based on the following elements such as Ti, Ge, Zn, Fe, Mn, Co, Zr, V, Ir, La, Ce, Li and Ca, preferably organometallic compounds based on these metals, such as salts of organic acids, alkoxides, acetylacetonates and the like, particularly preferably based on zinc, tin and titanium.

When using dicarboxylic acids or their anhydrides as component (a1), their esterification with component (a2) can take place before, simultaneously or after the transesterification. In a preferred embodiment, the process described in DE-A 23 26 026 is used for the production of modified polyalkylene terephthalates.

After the reaction of components (al) and (a2), the mixture is generally heated to a temperature under reduced pressure or in an inert gas stream, for example from nitrogen, with further heating

Temperature in the range from 180 to 260 ° C., the polycondensation to the desired molecular weight taking into account the molar ratio of the carboxyl end groups to hydroxyl end groups, which is chosen to be greater than 1, preferably greater than 2.

The desired end group ratio can be set

by a corresponding excess of component al,

- by a correspondingly long polycondensation time with simultaneous removal of the diol with an excess of component a2, or

by adding an appropriate amount of polyfunctional carboxylic acids or their derivatives, preferably dicarbon Acid anhydrides such as succinic anhydride, phthalic anhydride, pyromellitic anhydride or trimellitic anhydride if polyester P1 predominantly has hydroxyl end groups due to the use of an excess of component a2.

In order to avoid undesired degradation and / or side reactions, stabilizers can also be added in this process step if desired. Such stabilizers are, for example, those in EP-A 13 461, US 4,328,049 or in B. Fortunato et al., Polymer Vol. 35, No. 18, pp. 4006 to 4010, 1994, Butterworth-

Heinemann Ltd., described phosphorus compounds. Some of these can also act as deactivators of the catalysts described above. Examples include: organophosphite, phosphonous acid and phosphorous acid. As compounds which act only as stabilizers are exemplified: trialkyl phosphite, triphenyl phosphite, trialkyl phosphates, phenyl phosphate tri- and tocopherol (vitamin E, available for example as UVI nul ^® 2003AO (BASF)).

When using the biodegradable copolymers according to the invention, for example in the packaging sector e.g. for foodstuffs, it is generally desirable to keep the content of the catalyst used as low as possible and to use no toxic compounds. In contrast to other heavy metals such as lead, tin, antimony, cadmium, chromium etc., titanium and zinc compounds are generally not toxic ("Sax Toxic Substance Data Book", Shizuo Fujiyama, Maruzen, KK, 360 S. (cited in EP-A 565,235), see also Römpp Chemie Lexikon Vol. 6, Thieme Verlag, Stuttgart, New York, 9th edition, 1992, pp. 4626 to 4633 and 5136 to 5143). Examples include: dibutoxydiacetoacetoxytitanium, tetrabutyl orthotitanate and zinc (II) acetate.

The weight ratio of catalyst to biodegradable polyester P1 is usually in the range from 0.01: 100 to 3: 100, preferably from 0.05: 100 to 2: 100, it also being possible to use smaller amounts, such as 0.0001, for highly active titanium compounds : 100.

The catalyst can be used right at the start of the reaction, immediately shortly before the excess diol is separated off or, if desired, also distributed in several portions during the production of the biodegradable polyester P1. If desired, various catalysts or mixtures thereof can also be used. The biodegradable polyesters P2 according to the invention are characterized by a molecular weight (M _n ) in the range from 5,000 to 80,000, preferably from 6,000 to 45,000, particularly preferably from 10,000 to 40,000 g / mol, a viscosity number in the range from 30 to 450 , preferably from 50 to 400 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight polyester P2 at a temperature of 25 ° C.) and a melting point have in the range from 50 to 235, preferably from 60 to 235 ° C. and have both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being chosen to be greater than one, preferably greater than two.

According to the invention, the biodegradable polyesters P2 are obtained by reacting a mixture consisting essentially of

(bl) a mixture consisting essentially of

20 to 95, preferably from 25 to 80, particularly preferably from 30 to 70 mol% of adipic acid or ester-forming derivatives thereof or mixtures thereof,

5 to 80, preferably from 20 to 75, particularly preferably from 30 to 70 mol% of terephthalic acid or ester-forming derivatives thereof or mixtures thereof, and

the sum of the individual mole percentages being 100 mol%,

(b2) dihydroxy compound (a2),

the molar ratio of (bl) to (b2) being in the range from 0.4: 1 to 1.5: 1, preferably from 0.6: 1 to 1.1: 1,

(b3) from 0.01 to 100, preferably from 0.1 to 80% by weight, based on component (b1), a hydroxycarboxylic acid B1, and

(b4) from 0 to 5, preferably from 0 to 4, particularly preferably from 0.01 to 3.5 mol%, based on component (b1), compound D, where the hydroxycarboxylic acid B1 is defined by the formulas Ia or Ib

H0 - [- C (0) G — 0—] _p H - rl - rCc <o0) .— a G— (0—] _r -

Ia Ib

in which p is an integer from 1 to 1500, preferably from 1 to 1000 and r is 1, 2, 3 or 4, preferably 1 and 2, and G represents a radical which is selected from the group consisting of phenylene, - (CH ₂ ) _n -, where n is an integer of 1, 2, 3, 4 or 5, preferably 1 and 5, -C (R) H- and -C (R) HCH ₂ , where R represents methyl or ethyl.

The biodegradable polyesters P2 are expediently prepared analogously to the preparation of the polyester P1, it being possible for the hydroxycarboxylic acid B1 to be added both at the start of the reaction and after the esterification or transesterification stage.

In a preferred embodiment, the hydroxycarbonic acid B1 used is: glycolic acid, D-, L-, D, L-lactic acid, 6-hydroxyhexanoic acid, their cyclic derivatives such as glycolide (1,4-dioxane-2,5-dione ), D-, L-dilactide (3, 6-dimethyl-l, 4-dioxane-2,5-dione), p-hydroxybenzoic acid and their oligomers and polymers such as 3-polyhydroxybutyric acid, polyhydrox valeric acid, polylactide (for example as EcoPLA ^® (Fa. Cargill)), or a mixture of 3-polyhydroxybutyric acid and polyhydroxy valeric acid (the latter is available under the name Biopol ^® by Zeneca), particularly preferably for the preparation of Poly ester P2, the low molecular weight and cyclic derivatives thereof.

The biodegradable polyesters Ql according to the invention are characterized by a molecular weight (M _n ) in the range from 5000 to 100000, preferably from 8000 to 80,000, by a viscosity number in the range from 30 to 450, preferably from 50 to 400 g / ml (measured in o -Dichlorobenzene / phenol (50/50 wt .-%) at a concentration of 0.5 wt.% Polyester Ql at a temperature of 25 ° C), and a melting point in the range of 50 to 235, preferably from 60 to 235 ° C, and have both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being greater than one, preferably greater than 2. According to the invention, the polyester Ql are obtained by reacting a mixture consisting essentially of

(cl) polyester PI and / or a polyester PWD,

(c2) 0.01 to 50, preferably from 0.1 to 40% by weight, based on (cl), hydroxycarboxylic acid B1,

and

(c3) 0 to 5, preferably from 0 to 4 mol%, based on component (a1) from the production of PI and / or PWD, compound D.

The biodegradable polyester PWD is generally obtainable by reacting essentially the components (a1) and (a2), the molar ratio of (a1) to (a2) being in the range from 0.4: 1 to 1.5 : 1, preferably from 0.6: 1 to 1.25: 1, with the proviso that the polyester PWD has a molecular weight (M _n ) in the range from 5000 to 50,000, preferably from 6,000 to 35,000, ql mol, a viscosity number in Range from 30 to 350, preferably from 50 to 300 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5 wt .-% polyester PWD at a temperature of 25 ° C) and a melting point in the range from 50 to 170, preferably from 60 to 160 ° C, and have both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being greater than one, preferably greater than 2 , chooses.

The reaction of the polyester P1 and / or PWD with the hydroxycarboxylic acid B1, if desired in the presence of the compound D, is preferably carried out in the melt at temperatures in the range from 120 to 260 ° C. under an inert gas atmosphere, if desired also under reduced pressure. You can work batchwise or continuously, for example in stirred tanks or (reaction) extruders.

If desired, the reaction can be accelerated by adding known transesterification catalysts (see those described above in the preparation of the polyester P1).

A preferred embodiment relates to polyester Q1 with block structures formed from the components P1 and B1: when cyclic derivatives of B1 (compounds Ib) are used, when reacting with the biodegradable polyester P1 by a so-called "ring-opening polymerization", triggered by the end groups of P1, in a manner known per se with polyester Ql Block structures are obtained (for "ring-opening polymerization" see Encycl. Of Polymer. Science and Eng. Vol. 12, 2nd Ed., John Wiley & Sons, 1988, pp. 36 to 41). If desired, the reaction can be carried out with the addition of customary catalysts, such as the transesterification catalysts already described above, tin octanoate is particularly preferred (see also Encycl. Of Polymer. Science and Eng. Vol. 12, 2nd ed., John Wiley & Sons, 1988, pp. 36 to 41).

When using components B1 with higher molecular weights, for example with a p of greater than 10 (ten), the desired block structures can be obtained by reaction with the polyesters P1 in stirred tanks or extruders through the choice of reaction conditions, such as temperature, residence time and addition of Transesterification catalysts such as those mentioned above can be obtained. From J. of Appl. Polym. Sei., Vol. 32, pp. 6191 to 6207, John Wiley & Sons, 1986 and from Makromol. Chemie, Vol. 136, pp. 311 to 313, 1970 discloses that block copolymers and then random copolymers can first be obtained from polyesters in the melt from a blend by the reaction of transesterification reactions.

The biodegradable polyesters Q2 according to the invention are characterized by a molecular weight (M _n ) in the range from 6000 to 60,000, preferably from 8,000 to 50,000, particularly preferably from 10,000 to 40,000 g / mol, by a viscosity number in the range from 30 to 340, preferably from 50 to 300 g / ml (measured in o-dichlorobenzene / phenol (50/50% by weight) at a concentration of 0.5% by weight polyester Q2 at a temperature of 25 ° C.), and a melting point in the range from 50 to 170 ° C, preferably from 60 to 160 ° C.

According to the invention, the polyesters Q2 are obtained by reacting a mixture consisting essentially of

(dl) from 95 to 99.9, preferably from 96 to 99.8, particularly preferably from 97 to 99.65% by weight of polyester Pl and / or

Polyester PWD according to claim 3,

(d2) from 0.1 to 5, preferably 0.2 to 4, particularly preferably from 0.35 to 3% by weight of a bisoxazoline Cl and

(d3) from 0 to 5, preferably from 0 to 4 mol%, based on component (a1) from the production of PI and / or PWD, compound D. According to previous observations, bisoxazoline Cl can be used in all common bisoxazolines. Corresponding bisoxazolines are described, for example, in DE-A 39 15 874 (commercially available under the name Loxamid®). Further bisoxazolines are described in WO 94/03523 (PCT / EP 93/01986).

Particularly preferred bisoxazolines C1 are bisoxazolines of the general formula II

The bisoxazolines C1 of the general formula II (component d2) are generally obtainable by the process from Angew. Chem. Int. Edit., Vol. 11 (1972), pp. 287-288. Particularly preferred bisoxazolines are those in which R ^{1 is} a single bond, a (CH ₂ ) _q -alkylene group with q = ₂ , 3 or 4, such as methylene, ethane-1,2-diyl, propane-1,3-diyl , Propane-l, 2-diyl, butane-1, 4-diyl or a phenylene group. Particularly preferred bisoxazolines are 2,2'-bis (2-oxazoline), bis (2-oxazolinyl) methane, 1,2-bis (2-oxazolinyl) ethane, 1,3-bis (2-oxazolinyl) propane, 1 , 4-bis (2-oxazolinyl) butane, 1,4-bis (2-oxazolinyl) benzene, 1,2-bis (2-oxazolinyl) benzene and 1,3-bis (2-oxazolinyl) benzene.

The polyester Pl and / or PWD is preferably reacted with the bisoxazoline Cl in the melt (see also: J. Appl. Polym. Science, Vol. 33, pp. 3069-3079 (1987)), care being taken that if possible no side reactions occur which can lead to crosslinking or gel formation. In a special embodiment, the reaction is usually carried out at temperatures in the range from 120 to 260 ° C., preferably from 130 to 240 ° C., particularly preferably 140 to 220 ° C., the addition of the bisoxazoline advantageously in several portions or continuously.

If desired, the reaction of the polyester Pl and / or the PWD with the bisoxazoline Cl can also be carried out in the presence of common inert solvents such as toluene, methyl ethyl ketone or dimethylformamide ("DMF") or mixtures thereof, where the reaction temperature is generally in the range from 80 to

200, preferably from 90 to 150 ° C.

The reaction with the bisoxazoline Cl can be carried out batchwise or continuously, for example in stirred tanks, reaction extruders or via mixing heads.

Although the theoretical optimum for the reaction of Pl and / or PWD with bisoxazolines Cl with a molar ratio of the oxazoline function to Pl (or PWD) carboxyl end group (polyester Pl and / or PWD with predominantly carboxyl end groups are particularly preferred ) of 1: 1, the reaction can be carried out without technical problems even in molar ratios of 1: 3 to 1.5: 1. At the molar ratios of> 1: 1, preferably> 2: 1 according to the invention, a dicarboxylic acid, preferably selected from the group consisting of adipic acid, succinic acid, terephthalic acid and isophthalic acid, can be added during the reaction or after the reaction, if desired .

The biodegradable polymers TI according to the invention are characterized by a molecular weight (M _n ) in the range from 10,000 to 100,000, preferably from 11,000 to 80,000, preferably from 11,000 to 50,000 g / mol, with a viscosity number in the range from 30 to 450, preferably from 50 to 400 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polymer TI at a temperature of 25 ° C.) and a melting point in the range from 50 to 235, preferably from 60 to 235 ° C.

The biodegradable polymers TI are obtained according to the invention by using a polyester Ql according to claim 3

(el) 0.1 to 5, preferably from 0.2 to 4, particularly preferably from 0.3 to 2.5% by weight, based on the polyester Ql, bisoxazoline Cl and with

(e2) 0 to 5, preferably from 0 to 4 mol%, based on component (a1) from the production of PI and / or PWD and polyester Ql, brings compound D to the reaction.

A chain extension is usually achieved in this way, the polymer chains obtained preferably having a block structure.

The reaction is usually carried out analogously to the preparation of the polyester Q2. The biodegradable polymers T2 according to the invention are characterized by a molecular weight (M _n ) in the range from 10,000 to 100,000, preferably from 11,000 to 80,000, particularly preferably from 11,000 to 50,000 g / mol, with a viscosity number in the range from 30 to 450, preferably from 50 to 400 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polymer T2 at a temperature of 25 ° C.) and one Melting point in the range from 50 to 235, preferably from 60 to 235 ° C.

According to the invention, the biodegradable polymers T2 are obtained by reacting the polyester Q2 with

(fl) 0.01 to 50, preferably 0.1 to 40 wt .-%, based on the polyester Q2, the hydroxycarboxylic acid B1 and with

(f2) 0 to 5, preferably from 0 to 4 mol%, based on component (a1) from the production of PI and / or PWD and of the polyester Q2, compound D,

expediently proceeding analogously to the reaction of polyester P1 with hydroxycarboxylic acid B1 to polyester ql.

The biodegradable polymers T3 according to the invention are characterized by a molecular weight (M _n ) in the range from 10,000 to 100,000, preferably from 11,000 to 80,000 g / mol, a viscosity number in the range from 30 to 450, preferably from 50 to 400 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polymer T3 at a temperature of 25 ° C.) and a melting point in the range from 50 to 235, preferably from 60 to 235 ° C.

According to the invention, the biodegradable polymers T3 are obtained by (gl) polyester P2, or (g2) a mixture consisting essentially of polyester P1 and 0.01 to 50, preferably 0.1 to 40% by weight, based on the polyester P1, hydroxycarboxylic acid B1, or (g3) a mixture consisting essentially of polyesters P1, which have a different composition from one another, with

0.1 to 5, preferably from 0.2 to 4, particularly preferably from 0.3 to 2.5% by weight, based on the amount of the polyesters used, bisoxazoline Cl and

with 0 to 5, preferably from 0 to 4 mol%, based on the respective molar amounts of component (al) used to prepare the polyesters (g1) to (g3) used, bond D, to the reaction, the reactions advantageously being carried out analogously to the preparation of the polyester Q2 from the polyesters P1 and / or PWD and the bisoxazolines C1.

In a preferred embodiment, polyester P2 is used, the repeating units of which are randomly distributed in the molecule.

However, it is also possible to use polyester P2 whose polymer chains have block structures. Such polyesters P2 are generally accessible by appropriate selection, in particular of the molecular weight, of the hydroxycarboxylic acid B1. According to previous observations, this is generally done when using a high molecular weight hydroxycarboxylic acid B1, in particular with a p greater than 10, only an incomplete transesterification, for example also in the presence of the deactivators described above (see J.of Appl. Polym. Sc. Vol. 32, pp. 6191 to 6207, John Wiley & Sons, 1986, and Makrom. Chemie, Vol. 136, Pp. 311 to 313, 1970). If desired, the reaction can also be carried out in solution with the solvents mentioned in the preparation of the polymers TI from the polyesters Ql and the bisoxazoline Cl.

According to the invention, the biodegradable thermoplastic molding compositions T4 are obtained by, in a manner known per se, preferably with the addition of customary additives such as stabilizers, processing aids, fillers, etc. (see J. of Appl. Polym. Sc, Vol. 32, Pp. 6191 to 6207, John Wiley & Sons, 1986; WO 92/0441; EP 515,203; KunstStoff-Handbuch, Vol. 3/1, Carl Hanser Verlag Munich, 1992, pp. 24 to 28)

(hl) 99.5 to 0.5% by weight of polyester PI according to claim 1 or polyester Q2 according to claim 4 or polyester PWD according to claim 3

(h2) 0.5 to 99.5% by weight of hydroxycarboxylic acid Bl mixes.

In a preferred embodiment, high molecular weight hydroxycarboxylic acids B1 such as polycaprolactone or polylactide or polyglycolide or polyhydroxyalkanoates such as 3-polyhydroxybutyric acid with a molecular weight (M _n ) in the range from 10,000 to 150,000, preferably from 10,000 to 100,000 g / mol, or a mixture, are used 3-polyhydroxybutyric acid and polyhydroxyvaleric acid.

From WO 92/0441 and EP-A 515,203 it is known that high molecular weight polylactide is too brittle for most applications without the addition of plasticizers. In a preferred embodiment a blend starting from 0.5 to 20, preferably from 0.5 to 10% by weight of polyester PI according to claim 1 or polyester Q2 according to claim 4 or polyester PWD according to claim 3 and 99.5 to 80, preferably produce from 99.5 to 90% by weight of polylactide, which has a significant improvement in the mechanical properties, for example an increase in impact strength, compared to pure polylactide.

A further preferred embodiment relates to a blend which can be obtained by mixing from 99.5 to 40, preferably from 99.5 to 60% by weight polyester PI according to claim 1 or polyester Q2 according to claim 4 or polyester PWD according to claim 3 and from 0.5 to 60, preferably from 0.5 to 40% by weight of a high molecular weight hydroxycarboxylic acid B1, particularly preferably polylactide, polyglycolide, 3-polyhydroxybutyric acid and polycaprolactone. Such blends can be completely biodegraded and, according to the observations made to date, have very good mechanical properties.

According to previous observations, the thermoplastic molding compositions T4 are preferably obtained by observing short mixing times, for example when the mixing is carried out in an extruder. By selecting the mixing parameters, in particular the mixing time and, if desired, the use of deactivators, molding compositions are also accessible which predominantly have blend structures, i.e. the mixing process can be controlled in such a way that transesterification reactions can also take place at least in part.

In a further preferred embodiment, 0 to 50, preferably 0 to 30 mol% of the adipic acid, or its ester-forming derivatives or mixtures thereof, can be achieved by at least one other aliphatic C ₄ -C 10 -o or cycloaliphatic Cs-Cio-dicarboxylic acid or dimer fatty acid such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid or sebacic acid or an ester derivative such as their di-Ci-Cβ-alkyl ester or their anhydrides such as succinic anhydride, or their mixtures, replace, preferably succinic acid, succinic anhydride, sebacic acid, sebacic acid and di-Ci-Cβ-alkyl esters such as dimethyl, diethyl, di-n-propyl, diisobutyl, di-n-pentyl, dineopentyl, di-n-hexyl esters thereof, especially dimethyl succinic acid.

A particularly preferred embodiment relates to the use as component (a1) of the mixture of succinic acid, adipic acid and glutaric acid described in EP-A 7445 and their Ci-Cβ-alkyl esters, especially the dimethyl ester and diisobutyl ester.

In a further preferred embodiment, 0 to 50, preferably 0 to 40, mol% of the terephthalic acid or its ester-forming derivatives, or mixtures thereof, by at least one other aromatic dicarboxylic acid such as isophthalic acid, phthalic acid or 2,6-naphthalenedicarboxylic acid, preferably isophthalic acid, or an ester derivative such as a di-Ci-Cβ-alkyl ester, especially the dimethyl ester, or mixtures thereof.

In general, it should be noted that the different polymers according to the invention can be worked up in the customary manner by isolating the polymers, or, in particular if the polyesters P1, P2, Q1 and Q2 are to be reacted further, by not isolating the polymers but processing them immediately .

The polymers according to the invention can be applied to coating substrates by rolling, brushing, spraying or pouring. Preferred coating underlays are those that are compostable or rot like moldings made of paper, cellulose or starch.

The polymers according to the invention can also be used for the production of moldings which are compostable. The following may be mentioned as examples of shaped bodies: disposable items such as dishes, cutlery, garbage bags, films for agriculture for the early harvest, packaging films and containers for growing plants.

Furthermore, the polymers according to the invention can be spun into threads in a manner known per se. If desired, the threads can be drawn by conventional methods, drawing twists, drawing bobbins, drawing warping, drawing finishing and drawing texturing. The stretching to so-called plain yarn can take place in one and the same operation (fully drawn yarn or fully oriented yarn), or in a separate operation. Stretch warping, stretch finishing and stretch texturing are generally carried out in a separate process from spinning. The threads can be further processed into fibers in a manner known per se. Flat structures are then accessible from the fibers by • weaving, knitting or knitting.

If desired, the moldings, coating compositions and threads etc. described above can also contain fillers which are used in any stage or during the polymerization process subsequently, for example, can be incorporated into a melt of the polymers according to the invention.

Based on the polymers according to the invention, from 0 to 80% by weight of fillers can be added. Suitable fillers are, for example, carbon black, starch, lignin powder, cellulose fibers, natural fibers such as sisal and hemp, iron oxides, clay minerals, ores, calcium carbonate, calcium sulfate, barium sulfate and titanium dioxide. The fillers can also contain stabilizers such as tocopherol (vitamin E), organic phosphorus compounds, mono-, di- and polyphenols, hydroquinones, diarylamines, thioethers, UV stabilizers, nucleating agents such as talc and lubricants and mold release agents Based on hydrocarbons, fatty alcohols, higher carboxylic acids, metal salts of higher carboxylic acids such as calcium and zinc stearate, and montan waxes. Such stabilizers etc. are described in detail in Kunststoff-Handbuch, Vol. 3/1, Carl Hanser Verlag, Munich, 1992, pp. 24 to 28.

The polymers according to the invention can also be colored as desired by adding organic or inorganic dyes. In the broadest sense, the dyes can also be regarded as fillers.

A particular field of application of the polymers according to the invention relates to their use as a compostable film or a compostable coating as the outer layer of diapers. The outer position of the diapers effectively prevents the passage of liquids which are absorbed by the fluff and superabsorbers, preferably biodegradable superabsorbers, for example based on crosslinked polyacrylic acid or crosslinked polyacrylamide, in the inside of the diaper. A fiber fleece made of a cellulose material can be used as the inner layer of the diaper. The outer layer of the diapers described is biodegradable and thus compostable. It disintegrates during composting, so that the entire diaper rots, while diapers provided with an outer layer made of, for example, polyethylene cannot be composted without prior comminution or costly separation of the polyethylene film.

Another preferred use of the polymers and molding compositions according to the invention relates to the production of adhesives in a manner known per se (see, for example, Encycl. Of Polym. Sc. And Eng. Vol. 1, "Adhesive Compositions", pp. 547 to 577). Analogous to the teaching of EP-A 21042, the polymers and molding compositions according to the invention can also be processed with suitable tackifying thermoplastic resins, preferably natural resins, by the methods described there. Analogous to the teaching of DE-A 4,234,305 the polymers and molding compositions according to the invention can also be further processed into solvent-free adhesive systems such as hot-melt films.

Another preferred area of application relates to the production of completely degradable blends with starch mixtures (preferably with thermoplastic starch as described in WO 90/05161) analogously to the process described in DE-A 42 37 535. According to previous observations, the polymers and thermoplastic molding compositions according to the invention can advantageously be used as a synthetic blend component on account of their hydrophobic nature, their mechanical properties, their complete biodegradability, their good compatibility with thermoplastic starch and not least because of their favorable raw material base.

Further areas of application relate, for example, to the use of the polymers according to the invention in agricultural mulch, packaging material for seeds and nutrients, substrate in adhesive films, baby panties, bags, bed sheets, bottles, boxes, dust bags, labels, pillow cases, protective clothing, hygiene articles, handkerchiefs, toys and wipers .

Another use of the polymers and molding compositions according to the invention relates to the production of foams, the procedure generally being known (see EP-A 372,846; Handbook of Polymeric foams and Foa Technology, Hanser Publisher, Munich, 1991, Pp. 375 to 408). Usually, the polymer or molding composition according to the invention is first melted, if desired with addition of up to 5% by weight of compound D, preferably pyromellitic dianhydride and trimellitic anhydride, then mixed with a blowing agent and the mixture thus obtained is subjected to reduced pressure by extrusion, where the foaming arises.

The advantages of the polymers according to the invention compared to known biodegradable polymers lie in a cheap raw material base with readily available starting materials such as adipic acid, terephthalic acid and common diols, in interesting mechanical properties by combining "hard" (through the aromatic dicarboxylic acids such as, for example, terephthalic acid) and "Soft" (due to the aliphatic dicarboxylic acids, such as adipic acid) segments in the polymer chain and the variation of the applications by simple modifications, in a good degradation behavior by microorganisms, especially in the compost and in the soil, and in a certain resistance to Microorganisms in aqueous systems at room temperature, which for many applications rich is particularly advantageous. The statistical attack of the aromatic dicarboxylic acids of the components (a1) in various polymers enables the biological attack and thus achieves the desired biodegradability.

It is particularly advantageous about the polymers according to the invention that both biodegradation behavior and mechanical properties can be optimized for the respective application by means of tailored formulations.

Furthermore, depending on the production process, it is advantageously possible to obtain polymers with predominantly randomly distributed monomer units, polymers with predominantly block structures and polymers with a predominantly blend structure or blends.

Examples

Enzyme test

The polymers were cooled in a mill with liquid nitrogen or dry ice and finely ground (the larger the surface of the ground material, the faster the enzymatic breakdown). To actually carry out the enzyme test, 30 mg of finely ground polymer powder and 2 ml of a 20 mmol aqueous K ₂ HP0 ₄ / KH ₂ P0 ₄ buffer solution (pH value: 7.0) were placed in an Eppendorf reagent tube (2 ml) and 3 h equilibrated on a swivel at 37 ° C. Then 100 units of lipase from either Rhizopus arrhi- zu, Rhizopus delemar or Pseudomonas pl. added and incubated for 16 h at 37 ° C with stirring (250 rpm) on the swivel. The reaction mixture was then passed through a Millipore ^® membrane

(0.45 μm) filtered and the DOC (dissolved organic carbon) of the filtrate measured. Analogously, a DOC measurement was carried out only with buffer and enzyme (as enzyme control) and one only with buffer and sample (as blank value).

The ΔDOC values determined (DOC (sample + enzyme) -DOC (enzyme control) -DOC (blank value)) can be regarded as a measure of the enzymatic degradability of the samples. They are shown respectively in comparison with a measurement with powder of polycaprolactone ^® Tone P 787 (Union Carbide). When evaluating, it must be ensured that the data are not absolutely quantifiable. The relationship between the surface of the ground material and the speed of the enzymatic degradation has already been mentioned above. Furthermore, the enzyme activities can also fluctuate. The molecular weights were measured by means of gel permeation chromatography (GPC):

stationary phase: 5 MIXED B-polystyrene gel columns (7.5x300 mm, PL-gel 10 μ) from Polymer Laboratories;

Temperature control: 35 ° C.

mobile phase: tetrahydrofuran (flow: 1.2 ml / min)

Calibration: Molecular weight 500-10000000 g / mol with PS calibration kit from Polymer Laboratories.

In the oligomer range, ethylbenzene / 1,3-diphenylbutane / l, 3,5-triphenylhexane / 1,3,5,7-tetraphenyloctane / l, 3,5,7,9-pentaphenyl decane

Detection: RI (refractive index) Waters 410

UV (at 254 nm) Spectra Physics 100

The hydroxyl number (OH number) and acid number (SZ) were determined using the following methods:

(a) Determination of the apparent hydroxyl number

10 ml of toluene and 9.8 ml of acetylating reagent (see below) were added to approx. 1 to 2 g of exactly weighed test substance and the mixture was heated at 95 ° C. with stirring for 1 h. Then 5 ml of dist.

Water supplied. After cooling to room temperature, 50 ml of tetrahydrofuran (THF) were added and titrated potentiographically with ethanolic KOH standard solution against the turning point.

The test was repeated without test substance (blank sample).

The apparent OH number was then determined using the following formula:

apparent OH number c t-56.1- (V2-V1) / m (in mg KOH / g) where c = concentration of the ethanol. KOH standard solution in mol / 1, t = titer of ethanol. KOH standard solution m = weight in mg of test substance VI = consumption of standard solution with test substance in ml

V2 = consumption of the standard solution without test substance in ml

mean. Reagents used: ethanol. KOH standard solution, c - 0.5 mol / 1, titer 0.9933 (Merck, Art. R. 1.09114)

Acetic anhydride p.A. (Merck, Item No. 42) Pyridine p.A. (Riedel de Haen, Art.No. 33638) Acetic acid p.A. (Merck, Item No. 1,00063) Acetylation reagent: 810 ml pyridine, 100 ml

Acetic anhydride and 9 ml acetic acid water, deionized THF and toluene

(b) Determination of the acid number (SZ)

Approximately 1 to 1.5 g of test substance were weighed exactly and mixed with 10 ml of toluene and 10 ml of pyridine and then heated to 95 ° C. After dissolving, the mixture was cooled to room temperature, 5 ml of water and 50 ml of THF were added, and 0.1 N ethanol. KOH standard solution titrated.

The determination was repeated without test substance (blind sample)

The acid number was then determined using the following formula:

SZ - c-t-56.1- (VI-V2) / m (in mg KOH / g) where c is the concentration of the ethanol. KOH standard solution in mol / 1, t - titer of ethanol. KOH standard solution m - Weigh in mg of the test substance

VI = Consumption of the standard solution with test substance in ml V2 - Consumption of the standard solution without test substance in ml.

Reagents used:

ethanol. KOH standard solution, c - 0.1 mol / 1. Titer - 0.9913 (Merck, Item No. 9115)

Pyridine p.A. (Riedel de Haen, Art. No. 33638) Water, deionized THF and toluene

(c) Determination of the OH number

The OH number results from the sum of the apparent OH number and the SZ:

OH number - apparent OH number + SZ Used abbreviations:

DOC: dissolved organic carbon DMT: dimethyl terephthalate PCL: Polycaprolacton® Tone P 787 (Union Carbide) PMDA: pyromellitic dianhydride SZ: acid number TBOT: tetrabutyl orthotitanate

VZ: viscosity number (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of

0.5 wt .-% polymer at a temperature of 25 ° CT _m : "melting temperature" - temperature at which a maximum endothermic heat flow occurs (extremum of the DSC curves) T _g : glass transition temperature (midpoint of the DSC curves)

The DSC measurements were carried out with a DSC device 912 + Thermal Analyzer 990 from DuPont. The temperature and enthalpy calibration was carried out in the usual way. The sample weight was typically 13 mg. Heating and cooling rates - unless otherwise noted - were 20 K / min. The samples were measured under the following conditions: 1. heating run on samples in the delivery state, 2. rapid cooling from the melt, 3. heating run on samples cooled from the melt (samples from 2). The second DSC runs served to enable a comparison between the different samples after impressing a uniform thermal history.

Example 1 - Preparation of a polyester Pl

(a) 4672 kg of 1,4-butanediol, 7000 kg of adipic acid and 50 g of tin dioctoate were reacted in a nitrogen atmosphere at a temperature in the range from 230 to 240 ° C. After the majority of the water formed during the reaction had been distilled off, 10 g of TBOT were added to the reaction mixture. After the acid number had dropped below 1, excess 1,4-butanediol was distilled off under reduced pressure until an OH number of 56 was reached.

(b) 1.81 kg of the polyester from Example Ia, 1.17 kg of DMT, 1.7 kg of 1,4-butanediol and 4.7 g of TBOT and 6.6 g of PMDA were placed in a three-necked flask and added under a nitrogen atmosphere slow stirring heated to 180 ° C. The methanol formed during the transesterification reaction was distilled off. The mixture was heated to 230 ° C. in the course of 2 hours while increasing the stirring rate, and after a further hour 2 g 50% by weight aqueous phosphorous acid was added. Within 1 h, the pressure was reduced to 5 mbar and kept at 240 ° C. for 2.5 h <2 mbar, the 1-butanediol used in excess distilling off.

OH number: 1 mg KOH / g

SZ: 8.8 mg KOH / g

VZ: 98.2 g / ml

Tm: 93 ° C (DSC, delivery status), T _g : -39 ° C

Example 2 - Preparation of a polyester Q2

26.25 g of the bisoxaline bis (2-ricinol-2-oxazoline) -tetramethyl-xyloldiurethane (Loxamid® VEP 8523 from Fa.) Were added dropwise to 300 g of the copolyester from Example 1 a with stirring and under a nitrogen atmosphere at 200 ° C. in the course of 30 min Henkel, a bisoxazole made from ricinololoxazoline and 4,4'-diphenylmethane diisocyanate, prepared according to DE-A 39 15 874) was added, the melt viscosity increasing and the product turning brown.

OH number: 2 mg KOH / g SZ: 1.9 mg KOH / g

T ,,,: 97 ° C, T _g : -34 ° C (DSC, quickly cooled from 190 ° C) Enzyme test with Rhizopus arrhizus: ΔDOC: 357 mg / 1; for comparison with PCL: ΔDOC: 2588 mg / 1.

Example 3 - Preparation of another polyester Q2

To 300 g of the copolyester from Example 1 a, 6.9 g of the bisoxaline 1, -bis (2-oxazoline) butane were added dropwise with stirring and under a nitrogen atmosphere at 200 ° C. in the course of 10 min, the melt viscosity increasing and the product becoming brownish colored.

OH number: 3 mg KOH / g

SZ: 2 mg KOH / g

T _m : 99 ° C, T _g : -31 ° C (DSC, delivery status)

Enzyme test with Rhizopus arrhizus: ΔDOC: 421 mg / 1; for comparison with PCL: ΔDOC: 2588 mg / 1.

Claims

1. Biodegradable polyester P1, obtainable by reaction of a mixture consisting essentially of

(al) a mixture consisting essentially of

0 to 5 mol% of a compound containing sulfonate groups,

the sum of the individual mol percentages being 100 mol%, and

(a2) a dihydroxy compound selected from the group consisting of C ₂ -C ₆ -alkanediols and C ₅ -C -o-cycloalkanediols,

wherein the molar ratio of (al) to (a2) is selected in the range from 0.4: 1 to 1.5: 1, with the proviso that the polyester P1 has a molecular weight (M _n ) in the range from 5000 to 50,000 g / mol, a viscosity number in the range from 30 to 350 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polyester Pl at a temperature of 25 ° C) and have a melting point in the range from 50 to 170 ° C, and with the further proviso that from 0.01 to 5 mol%, based on the molar amount of component (a1) used, a compound D with at least three groups capable of ester formation for the production of the polyester P1, and the further requirement that the polyester P1 have both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being chosen to be greater than one.

2. Biodegradable polyester P2, obtainable by reaction of a mixture consisting essentially of

(bl) a mixture consisting essentially of 20 to 95 mol% of adipic acid or ester-forming derivatives thereof or mixtures thereof,

5 to 80 mol% of terephthalic acid or ester-forming derivatives thereof or mixtures thereof, and

0 to 5 mol% of a compound containing sulfonate groups,

the sum of the individual mole percentages being 100 mol%,

(b2) dihydroxy compound (a2),

the molar ratio of (bl) to (b2) being selected in the range from 0.4: 1 to 1.5: 1,

(b3) from 0.01 to 100% by weight, based on the component

(bl), a hydroxycarboxylic acid Bl, and

(b4) from 0 to 5 mol%, based on component (bl), compound D,

where the hydroxycarboxylic acid B1 is defined by the formulas Ia or Ib

in which p is an integer from 1 to 1500 and r is an integer from 1 to 4, and G is a radical which is selected from the group consisting of phenylene, - (CH ₂ ) _n -, where n is an integer Number from 1 to 5 denotes -C (R) H- and -C (R) HCH ₂ , where R is methyl or ethyl,

wherein the polyester P2 has a molecular weight (M _n ) in the range from 5000 to 80,000 g / mol, a viscosity number in the range from 30 to 450 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a Concentration of 0.5 wt .-% polyester P2 at a temperature of 25 ° C) and a melting point in the range of 50 to 235 ° C, and have both hydroxyl and carboxyl end groups Molar ratio of carboxyl end groups to hydroxyl end groups is greater than one.

3. Biodegradable polyester Ql, obtainable by reaction of a mixture consisting essentially of

(cl) polyester PI and / or a polyester PWD,

(c2) 0.01 to 50 wt .-%, based on (cl), hydroxy carboxylic acid Bl, and

(c3) 0 to 5 mol%, based on component (a1) from the production of PI and / or PWD, compound D, the polyester PWD being obtainable by reaction of essentially the components

(al) and (a2), the molar ratio of (al) to (a2) being selected in the range from 0.4: 1 to 1.5: 1, with the proviso that the polyester PWD has a molecular weight (M _n ) in the range from 5000 to 50,000 g / mol, a viscosity number in the range from 30 to 350 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight) % Polyester PWD at a temperature of 25 ° C) and a melting point in the range from 50 to 170 ° C, the polyester Ql having a molecular weight (M _n ) in the range from 5000 to 100000 g / mol, a viscosity number in the range of 30 to 450 g / ml (measured in o-dichlorobenzene / phenol (50/50 weight ratio) at a concentration of 0.5

Wt .-% polyester Ql at a temperature of 25 ° C) and a melting point in the range of 50 to 235 ° C, and polyester PWD and polyester Ql have both hydroxyl and carboxyl end groups, the molar ratio of carboxyl end groups to choose hydroxyl end groups greater than one.

4. Biodegradable polyester Q2 with a molecular weight (M _n ) in the range from 6000 to 60,000 g / mol, a viscosity number in the range from 30 to 340 g / ml (measured in o-dichlorobenzene / phenol (50/50 Wt .-%) at a concentration of 0.5 wt .-% polyester Q2 at a temperature of 25 ° C) and a melting point in the range of 50 to 170 ° C, obtainable by reaction of a mixture consisting essentially of (dl) from 95 to 99.9% by weight of polyester Pl and / or polyester PWD according to claim 3,

(d2) from 0.1 to 5% by weight of a bisoxazoline C1, the sum of the individual mole percentages

Is 100 mol%,

(d3) from 0 to 5 mol%, based on component (al) from the production of PI and / or PWD, compound D.

5. Biodegradable polymers TI with a molecular weight (M _n ) in the range from 10,000 to 100,000 g / mol, with a viscosity number in the range from 30 to 450 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at one

Concentration of 0.5 wt .-% polymer TI at a temperature of 25 ° C) and a melting point in the range of 50 to 235 ° C, obtainable by reacting the polyester Ql according to claim 3 with (el) 0.1 to 5 wt .-%, based on the polyester Ql, bis-oxazoline Cl and with (e2) 0 to 5 mol%, based on component (a1) from the production of polyester Ql via the polyester P1 and / or PWD , Connection D.

6. Biodegradable polymers T2 with a molecular weight (M _n ) in the range from 10,000 to 100,000 g / mol, with a

Viscosity number in the range from 30 to 450 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polymer T2 at a temperature of 25 ° C.) and one Melting point in the range from 50 to 235 ° C, obtainable by reacting the polyester with Q2

(fl) 0.01 to 50 wt .-%, based on polyester Q2, hydroxycarboxylic acid B1 and with

(f2) 0 to 5 mol%, based on component (a1) from the production of polyester Q2 via the polyester P1 and / or PWD, compound D.

, Biodegradable polymers T3 with a molecular weight (M _n ) in the range of 10,000 to 100,000 g / mol, with a

Viscosity number in the range from 30 to 450 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50/50) at a concentration of 0.5% by weight of polymer T3 at a temperature of 25 ° C.) and one Melting point in the range of 50 to 235 ° C, obtainable by reacting (gl) polyester P2, or

(g2) a mixture consisting essentially of polyester P1 and 0.01 to 50% by weight, based on polyester P1, hydroxycarboxylic acid B1, or

(g3) a mixture consisting essentially of polyesters P1 which have a different composition from one another,

with 0.1 to 5 wt .-%, based on the amount of used

Polyester, bisoxazoline Cl as well

with 0 to 5 mol%, based on the respective molar amounts of component (al) which were used to prepare the polyesters (g1) to (g3) used, compound D.

8. Biodegradable thermoplastic molding compositions T4, obtainable by mixing in a manner known per se from

(h2) 0.5 to 99.5% by weight of hydroxycarboxylic acid Bl.

9. A process for producing the biodegradable polyester P1 according to claim 1 in a manner known per se, characterized in that a mixture consisting essentially of

(al) a mixture consisting essentially of

0 to 5 mol% of a compound containing sulfonate groups,

the sum of the individual mol percentages being 100 mol%, and (a2) a dihydroxy compound selected from the group consisting of C ₂ -Cg alkanediols and Cs-Cio-cycloalkanediols,

wherein the molar ratio of (al) to (a2) is selected in the range from 0.4: 1 to 1.5: 1, and from 0.01 to 5 mol%, based on the molar amount of component (al) used, a compound D with at least three groups capable of ester formation is reacted.

10. The method for producing the biodegradable polyester P2 according to claim 2 in a manner known per se, characterized in that a mixture consisting essentially of

(bl) a mixture consisting essentially of

20 to 95 mol% of adipic acid or ester-forming derivatives thereof or mixtures thereof,

0 to 5 mol% of a compound containing sulfonate groups,

the sum of the individual mole percentages being 100 mol%,

(b2) dihydroxy compound (a2),

(b3) from 0.01 to 100% by weight, based on component (bl), of a hydroxycarboxylic acid B1, and

(b4) from 0 to 5 π.ol%, based on component (bl), compound D,

where the hydroxycarboxylic acid B1 is defined by the formulas Ia or Ib H0- [C (0) G 0—. Ph [-C (O) GO—] _r -l

Ia Ib

in which p is an integer from 1 to 1500 and r is an integer from 1 to 4, and G represents a radical which is selected from the group consisting of phenylene, - (CH ₂ ) _n -, where 10 for n is an integer from 1 to 5, -C (R) H- and -

C (R) HCH ₂ , where R is methyl or ethyl, causes the reaction.

11. A process for producing the biodegradable polyester 15 Ql according to claim 3 in a manner known per se, characterized in that a mixture consisting essentially of

(cl) polyester PI and / or a polyester PWD,

20th

(c2) 0.01 to 50% by weight, based on (cl), hydroxycarboxylic acid B1, and

(c3) 0 to 5 mol%, based on component (al) from 25 of the production of PI and / or PWD, compound

D,

to react.

30 12. A process for producing the biodegradable polyester Q2 according to claim 4 in a manner known per se, characterized in that a mixture consisting essentially of

35 (dl) from 95 to 99.9% by weight of polyester Pl and / or polyester PWD according to claim 3,

(d2) from 0.1 to 5% by weight of a bisoxazoline Cl and

40 (d3) from 0 to 5 mol%, based on component (a1) from the production of PI and / or PWD, compound D

to react.

45 13. A process for the preparation of the biodegradable polymers TI according to claim 5 in a manner known per se, characterized ge indicates that polyester Ql according to claim 3 with (el) 0.1 to 5 wt .-%, based on the polyester Ql , Bisoxazoline Cl and with (e2) 0 to 5 mol%, based on component (al) from the preparation of polyester Ql via polyester P1 and / or PWD, compound D to the reaction.

14. A process for the preparation of the biodegradable polymers T2 according to claim 6 in a manner known per se, characterized in that polyester Q2 with

(fl) 0.01 to 50% by weight, based on polyester Q2,

Hydroxycarboxylic acid Bl and with

(f2) 0 to 5 mol%, based on component (al) from the production of polyester Q2 over polyester

Pl and / or PWD, connection D,

to react.

15. A process for the preparation of the biodegradable polymers T3 according to claim 7 in a manner known per se, characterized in that one

(gl) polyester P2, or

with 0.1 to 5 wt .-%, based on the amount of polyester used, bisoxazoline Cl

with 0 to 5 mol%, based on the respective molar amounts of component (a1) which were used to prepare the polyesters (g1) to (g3) used, brings compound D to the reaction.

16. A process for the preparation of the biodegradable thermoplastic molding compositions T4 according to claim 8 in a manner known per se, characterized in that 99.5 to 0.5% by weight polyester PI according to claim 1 or polyester Q2 according to claim 4 or polyester PWD according to claim 3 with 0.5 to 99.5 wt .-% hydroxycarboxylic acid Bl.

17. Use of the biodegradable polymers according to claims 5 to 7 or of the thermoplastic molding compositions

Claim 8 or produced according to claims 9 to 16 for the production of compostable moldings.

18. Use of the biodegradable polymers according to claims 10 to 7 of the thermoplastic molding compositions

Claim 8 or produced according to claims 9 to 16 for the production of adhesives.

15 19. Compostable moldings obtainable by the use according to claim 17.

20. Adhesives obtainable by use according to claim 18.

20th

21. Use of the biodegradable polymers according to claims 1 to 7 or the thermoplastic molding compositions according to claim 8 or produced according to claims 9 to 16 for the production of biodegradable blends containing in

25 essential the polymers and starch according to the invention.

22. Biodegradable blends obtainable by the use according to claim 21.

23. The method for producing biodegradable blends according to claim 22 in a manner known per se, characterized in that starch is mixed with the polymers according to the invention.

^ 5 2. Use of the biodegradable polymers according to claims 1 to 7 or the thermoplastic molding compositions according to claim 8 or produced according to claims 9 to 16 for the production of biodegradable foams.

* 0 25. Biodegradable foams obtainable through the use according to claim 24.

45 Biodegradable polymers, processes for their production and their use for the production of biodegradable moldings

Summary

Biodegradable polyester P1, obtainable by reaction of a mixture consisting essentially of

(al) a mixture consisting essentially of

0 to 5 mol% of a compound containing sulfonate groups, the sum of the individual mol percentages being 100 mol%, and

(a2) a dihydroxy compound selected from the group consisting of C ₂ -C 6 -alkanediols and Cs-Cio-cycloalkanediols,

the molar ratio of (al) to (a2) being selected in the range from 0.4: 1 to 1.5: 1,

with the proviso that the polyester P1 has a molecular weight (M _n ) in the range from 5000 to 50,000 g / mol, a viscosity number in the range from 30 to 350 g / ml (measured in o-dichlorobenzene / phenol (weight ratio 50 / 50) at a concentration of 0.5% by weight of polyester Pl at a temperature of 25 ° C.) and a melting point in the range from 50 to 170 ° C., and with the further proviso that from 0.01 up to 5 mol%, based on the molar amount of component (a1) used, uses a compound D with at least three groups capable of ester formation for the production of the polyester P1, and the further stipulation that the polyester P1 and hydroxyl and also have carboxyl end groups, the molar ratio of carboxyl end groups to hydroxyl end groups being chosen to be greater than one,

as well as other biodegradable polymers and thermoplastic molding compositions, processes for their production, their use for the production of biodegradable molded articles and adhesives, biodegradable molded articles, foams and blends with starch, obtainable from the polymers or molding compounds according to the invention.